Commercial and industrial paint spraying equipment employs a suction tube extending from the inlet port of the paint pump for withdrawing paint directly from a paint shipping container or other similar receptacle. A three-dimensional screen or filter is typically attached to the remote end of the suction tube for removing particulate matter from the paint before the paint enters the equipment. In order to position the remote end of the suction tube near the bottom of the paint container and thereby reduce the volume of unrecoverable paint between the remote end of the suction tube and the bottom of the paint container, the remote end of the suction tube is commonly projected into the internal chamber defined by the filter.
Unfortunately, the remote end of the suction tube on paint spraying equipment is susceptible to receiving frequent physical abuse during transportation and use of the equipment. Such physical abuse commonly results in structural damage to the filter medium surrounding the remote end of the suction tube with a resultant reduction in the functional surface area of the filter medium and occasional rupturing of the filter medium with resultant loss of filtration efficiency.
In order to achieve projection of the suction tube into the internal chamber defined by the filter medium, the suction tube is threaded continuously along the remote end for a distance sufficient to permit the filter assembly to travel the necessary distance along the tube. While effective for achieving the desired extension of the suction tube into the internal chamber, paint tends to collect within the threads on the suction tube and cannot be easily removed due to the inaccessible positioning of the tube within the filter. Once permitted to dry it becomes very difficult to remove the filter assembly from the suction tube.
Accordingly, a substantial need exists for (i) an inexpensive apparatus capable of protecting the filter medium against structural damage resulting from sudden contact between the filter medium and another object, and (ii) an inexpensive mechanism for sealingly securing the filter to the remote end of a paint sprayer suction tube with the remote end of the tube to projecting into the internal chamber defined by the filter medium which permits simple and easy removal and replacement of the filter after prolonged and repeated exposure of the mechanism to the media to be filtered including specifically, but not exclusively, latex paints, oil-based paints, block fillers and other pumpable coating compositions.